The invention relates to a jet regulator having a jet regulator housing, in the housing interior of which there is provided a perforated plate which has a multiplicity of throughflow holes for dividing the through-flowing water.
Jet regulators of the type mentioned in the introduction are already known in a wide variety of embodiments. Jet regulators of said type are mounted on the water outlet of a sanitary outlet fitting in order to generate a homogenous and laterally non-sputtering water jet. Jet regulators also exist which aerate the out-flowing water jet and, for this purpose, are designed to mix the through-flowing water with the ambient air.
For example, from DE 30 00 799 A1, an aerated jet regulator is already known which, in its jet regulator housing, has a perforated plate with a multiplicity of throughflow holes which are arranged in concentric hole circles on the perforated plate and which are intended to split up the water—flowing through the jet regulator housing into a corresponding number of individual jets. Since the throughflow holes constrict the clear throughflow cross section in the region of the perforated plate, the through-flowing water increases in speed in the throughflow holes, which, in accordance with the Bernoulli equation, results in a negative pressure on the outflow side of the perforated plate. Due to the negative pressure generated on the outflow side of the perforated plate, ambient air is drawn in, which ambient air can enter into the housing interior of the jet regulator housing through aeration openings provided in the housing wall and can mix there with the through-flowing water. In order that the through-flowing water is divided into individual jets by means of the perforated plate in a quiet manner, it is provided in the case of the jet regulator already known from DE 30 00 799 A1 inter alia that the throughflow holes have a hole section which is polygonal in cross section, downstream of which hole section there is provided a hole section which widens progressively in terms of cross section and which is cylindrical at the outflow side (see FIG. 4 in DE 30 00 799 A1). By means of throughflow holes of said type which have different sections, an individual jet which is of circular cross section and which flows out linearly is produced in each of the throughflow holes.
EP 1 273 724 B1 (=DE 601 01 909 T2) has already disclosed a jet regulator having a jet regulator housing, in the housing interior of which there is provided a perforated plate with throughflow holes which have a clear cross section which remains constant in the throughflow direction. Positioned downstream of the perforated plate in the throughflow direction is an impingement cone which forms a constriction in the throughflow cross section of the already known jet regulator. The individual jets generated in the perforated plate can entrain the ambient air in the housing interior of the jet regulator housing, and subsequently impinge on the oblique surface of the impingement cone such that the aerated individual jets with the entrained air are broken up and thoroughly mixed.
The already known jet regulators however require a certain throughflow rate and an adequate water pressure in the supply main network in order for there to be generated on the outflow side of the perforated plate, which serves as a jet splitter, a negative pressure sufficient to draw ambient air into the housing interior of the jet regulator housing. By contrast, the negative pressure generated in the case of a low throughflow rate and low water pressures is normally not sufficient to mix the ambient air with the through-flowing water.